It has some problems with version 5 of the 37 based cIOS, causing it to get stuck at times (usually after finishing a song when playing music games). However, the very same game works fine in uloader. And perhaps even USB loader GX as well (I haven't tested that well enough to know for sure, but it seems to work).

The thing is also a dilemma because uloader uses version 5 of the 37 based cIOS to run a fair amount of wiiware titles.

Oh, and not to forget: that same IOS can be used to play DLC of music games (unlike v4, no matter how you merge things). I know Waninkoko's latest revs can also pull that off, but it's still worth mentioning.